Stable synthetic material and method for preparing same

ABSTRACT

A composition of matter is provided including an inorganic porous material having wall portions defining mesopore-sized channels having a mean diameter of between about 15 Å and about 100 Å and a narrow diameter distribution of less than or equal to about 30 Å, the material having a void volume from the mesopore-sized channels of at least about 0.1 cc/g and a surface area of at least about 500 m 2  /g and having a number of hydroxyl groups of at least about 1.5 mmol of hydroxyl groups per gram of material, and exhibiting thermal and hydrothermal stability at temperatures up to about 500° C. Catalytic materials incorporating aluminum and other active metals, as well as a process for preparing the composition, are also disclosed.

CROSS REFERENCE TO RELATED APPLICATION

The instant application is a continuation-in-part of application Ser.No. 794,204 filed Jan. 31, 1997, which has matured into U.S. Pat. No.5,840,271 issued Nov. 24, 1998.

BACKGROUND OF THE INVENTION

The invention relates to a thermally and hydrothermally stable syntheticmaterial having a high void volume attributable to tortuousmesopore-sized channels having a mean diameter between about 15 Å andabout 100 Å and a narrow size distribution of less than or equal toabout 30 Å, and a process for preparing same, so as to provide anexcellent starting material for incorporation of active materials andthe like.

Amorphous silica-aluminas are commercially used catalysts in manyprocesses due to their acidity. The two most common methods forpreparing amorphous silica-alumina are the controlled deposition of analumina salt on a silica surface, and the co-precipitation of silica andalumina species from solution. In the first method, the silica surfaceis prepared from a silica gel, and alumina salt is hydrolyzed andprecipitated by addition of aqueous ammonia.

The first method, controlled deposition of alumina on silica gel, leadsto the generation of tetrahedrally coordinated aluminum, due to thecontrolled incorporation of the hydrolyzed aluminum atoms into thesilica structure. In practice, however, this method is not desirablebecause the porosity of the silica gel collapses upon thermal treatment,for example during calcination, thereby making the aluminum atomsinaccessible to hydrocarbon molecules or other materials to be treated,thereby diminishing the practical value of such composition forcommercial processes.

The second method, co-precipitation, leads undesirably to a large amountof octahedrally coordinated aluminum.

It is therefore evident that the need remains for a synthetic materialwherein alumina and other active materials can be incorporated ordeposited in tetrahedrally coordinated position with silica and whereinthe composition maintains its porous structure without collapsing duringcalcination and/or other high temperature processes.

It is therefore the primary object of the present invention to provide amaterial on which active materials can be deposited and dispersed whichmaterial is thermally and hydrothermally stable.

It is a further object of the present invention to provide a method forpreparing such a material.

Other objects and advantages of the present invention will appearhereinbelow.

SUMMARY OF THE INVENTION

In accordance with the invention, the foregoing objects and advantagesare readily attained.

According to the invention, a composition of matter is provided whichcomprises an inorganic porous material having wall portions definingmesopore-sized channels having a mean diameter of between about 15 Å andabout 100 Å and a narrow diameter distribution of less than or equal toabout 30 Å, said material having a void volume from said mesopore-sizedchannels of at least about 0.1 cc/g and a surface area of at least about500 m² /g and having a number of hydroxyl groups of at least about 1.5mmol of hydroxyl groups per gram of material, and exhibiting thermal andhydrothermal stability at temperatures up to about 500° C.

In further accordance with the present invention, a process is providedfor preparing an inorganic porous material in accordance with thepresent invention, which process comprising the steps of forming asolution of a hydrolyzable inorganic compound with a non-ionictensoactive organic molecule; inducing growth and condensation of asolid composition comprising an inorganic composition in intimatecontact with said organic molecule; and extracting said organic moleculewith a solvent so as to provide a porous solid composition having aporous structure and having a number of hydroxyl groups of at leastabout 1.5 mmol of hydroxyl groups per gram of material, wherein saidmaterial maintains said porous structure upon thermal and hydrothermaltreatments at temperatures of up to about 500° C.

In accordance with the present invention, solvent extraction andcalcination can be used, if desired, to control the number of hydroxylgroups present in the resulting inorganic porous material.

Further, an active material such as an active metal or non-metal,absorbent or adsorbent agents, and the like, may readily be depositeddirectly upon the inorganic porous material to provide a wide variety ofcatalysts useful in various applications in accordance with the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description of preferred embodiments of the present inventionfollows, with reference to the attached drawings, wherein:

FIG. 1 is the N₂ adsorption isotherm for the product of Example 1;

FIG. 2 is a derivative of the N₂ adsorption volume as a function of porediameter for the product of Example 1, showing its size distribution ofmesopores;

FIG. 3 shows the ²⁷ Al MAS NMR spectrum for a silica-alumina sampleprepared in accordance with the present invention, and a sample preparedthrough co-precipitation, as described in Example 3; and

FIG. 4 shows the infrared spectrum after pyridine adsorption at roomtemperature and desorption for two samples of materials prepared inaccordance with the present invention as described in Example 3.

DETAILED DESCRIPTION

The invention relates to a synthetic material which advantageouslypossesses high void volume generated by mesoporous channels with anarrow size distribution and which further exhibits enhanced stabilityunder thermal and hydrothermal treatment conditions. This material isideally suited, for example, as a support for catalytic components forvarious processes.

For metals to become effective catalytic components in their metallicstate, or as oxides, sulfides or mixtures thereof, it is important toeffectively disperse them on supports, to enhance their surface tovolume ratio. The ability of a support to effectively disperse activecatalytic components is associated to density of anchoring sites. Insilica, a preferred support in many catalytic applications, theanchoring sites are surface hydroxyl groups. The highest density ofhydroxyl groups in silica supports is observed in silica gels with adensity of between 2 and 3 hydroxyl groups per nm². This material,however, is not thermally or hydrothermally stable, and upon thesetreatments the material usually collapses, rendering the active sitesinaccessible to the reactant molecules. Because of this, other silicasources such as pyrogenic or precipitated silicas, are conventionallyused to disperse catalytic components due to superior thermal andhydrothermal stability. The hydroxyl concentration in these materials,however, is substantially lower than in silica gels, hampering theability of these silica forms to disperse active materials.

In accordance with the present invention, synthetic material is providedwith a hydroxyl group concentration similar to that of silica gel andwith the thermal and hydrothermal stability of other silica forms suchas pyrogenic or precipitated silicas.

According to the invention, a synthetic material is provided having ahigh void volume, preferably at least about 0.1 cc/g and more preferablyat least about 0.2 cc/g, wherein the void volume is attributable to orgenerated from tortuous channels defined in the material. The channelspreferably have a mean diameter between about 15 Å and about 100 Å and anarrow size distribution less than or equal to about 30 Å. The surfacearea of these channels is high, preferably at least 500 m² /g ofmaterial and more preferably at least about 800 m² /g, and it is coveredby a high concentration of hydroxyl groups, preferably at least about1.5 mmol of hydroxyl groups per gram of material. These advantageouscharacteristics allow the synthetic material of the present invention tobe used in treating a feedstock having a fraction of large-hydrocarbonmolecules. During such treatment, larger molecules are upgraded,converted or otherwise treated in sites within the mesoporous channels.In a different process, a component of the feedstock may also beseparated by selective adsorption into the mesoporous channels of thesynthetic material.

The synthetic material according to the invention also advantageouslyexhibits enhanced stability in the presence of steam and/or hightemperatures, for example up to at least about 500° C., making thematerial excellently suited for use in processes involving thermal andhydrothermal steps. It is believed that the enhanced stability ofmaterial of the present invention results from well structuredand\relatively thick walls of the material that define the mesoporoustortuous channels.

The narrow size distribution of mesoporous channels in the syntheticmaterial of the present invention is exhibited, for example, by anitrogen adsorption isotherm having sharp inflection points at P/P₀values of between about 0.05 and about 0.8, and a relatively flatisotherm above P/P₀ of 0.8, indicating mesopore pore size distributionof between about 15 Å and about 100 Å. This feature of the presentinvention is further exhibited by a plot of the derivative of N₂adsorption volume as a function of pore diameter which shows a narrowband of pore sizes preferably centered around a pore size of less thanor equal to about 40 Å (See Example 1 below, FIG. 2). In accordance withone aspect of the present invention, the material may preferably have ashort range order structure, which has enhanced resistance to breakdownwhen subjected to thermal and hydrothermal treatments. The preferredshort range order in the synthetic material of the present invention isexhibited, for example, by a high energy electron diffraction pattern(EDP) containing only diffuse halos at d-spacing larger than 20 Å. Oneor more halos may be exhibited. This short range order is indicative ofmaterial having structural features (believed to be the tortuouschannels) that repeat themselves substantially throughout the material,but in correlations where the feature extends only a few times (up toabout five times, while in the case of crystalline materials featurescan repeat themselves thousands, or at the very least hundreds oftimes). This material is referred to as a material having a repeat valueof less than or equal to about 5.

The concentration of surface hydroxyl groups is exhibited by physicalmethods such as the signal intensity between 0 and 5 ppm on a ¹ H MASNMR spectrum or by chemical methods such as titration with a selectivereagent such as trimethylchlorosilane.

In further accordance with the invention, a process for preparing thesynthetic material of the present invention is provided. Advantageously,the process serves to provide a synthetic material preferably havingshort range order and tortuous mesoporous channels formed thereinwherein the channels are defined by walls believed to have a thicknesssufficient to enhance resistance of the synthetic material to use inthermal and hydrothermal processes. This is advantageous in thatconventionally prepared materials either possess very wide mesopore sizedistributions (between 50 Å and 1000 Å) or possess poor thermal andhydrothermal stability in same rendering the conventionally preparedmaterials undesirable for many processes, especially those involvingtreatment of feedstocks having large organic molecule fractions.

According to the invention, an inorganic porous material is prepared byforming a solution of a hydrolyzable inorganic compound with non-ionictensoactive organic molecules. The solution is thoroughly mixed, andthen treated so as to induce the formation of a solid materialcomprising an inorganic composition in intimate contact with thenon-ionic surfactant or tensoactive organic molecules. Solids may beformed by gelation of the hydrolyzable inorganic compounds at pH valuesnear the isoelectric point of the inorganic species in solution, andfurther condensation of the gel to form a solid material by aging of thegel at low temperatures, between about 0° C. and 40° C., and/or bythermal treatment at temperatures between about 40° C. and 120° C.

The solid material so obtained is then preferably separated fromremaining liquid of the solution, for example by centrifugation, washedwith water, and dried at room temperature.

The washed and dried solid is then treated through solvent extraction soas to extract the non-ionic surfactant from the inorganic composition soas to provide an inorganic material with a high void volume of at leastabout 0.1 cc/g generated by or attributable to the tortuous channels,and having a mean diameter between about 15 Å and about 100 Å and anarrow size distribution of less than or equal to about 30 Å. As setforth above, the material formed in accordance with the process of thepresent invention preferably has a short range order structureindicating a material which is an intermediate case between crystalline(long-range) and disordered materials.

In accordance with the invention, the conditions inducing the growth andcondensation of the hydrolyzable compound are controlled so as to formchain-like polymeric inorganic species that favor attractiveinteractions (by hydrogen bonding and/or Van der Waals forces) with thepolar groups of the non-ionic surfactant. This may suitably be carriedout by providing and maintaining a pH of the solution which is equal toor within about ±2 pH numbers of the isoelectric point mean value of theinorganic species or combination of inorganic species in solution. Atthe isoelectric point the condensation step is relatively slow, and thehydrolyzable species tend to polymerize into linear molecules that areoccasionally cross-linked. These molecular chains entangle and formadditional branches. These chain-like species are pervious to thenon-ionic surfactant, facilitating the establishment of attractiveinteractions. At synthesis conditions far from the isoelectric point,the polymerization rate is fast, leading to the formation of more highlybranch ed clusters that are not penetrable, and cannot easily interactwith the non-ionic surfactant. Furthermore, near the isoelectric point,the hydrolyzed groups of the inorganic species in solution contain forthe most part hydroxyl groups, favoring attractive interactions with theelectron donor groups of the non-ionic surfactant by H bonding.

The pH of the solution may be adjusted according to the invention byadding acid to the solution, preferably hydrochloric acid (HCl),although other acids may also be used.

In accordance with the invention, the hydrolyzable inorganic compoundmay suitably be selected from the group consisting of chlorides,alkoxides, nitrates, hydroxides, sulphates, and mixtures thereof, amongothers, preferably nitrates, hydroxides and mixtures thereof. Also, theinorganic species in solution can be prepared by dissolution of an oxidewith an appropriate acid or base. Further, precursors to the oxides maybe used, such as colloidal silica, alumina sols, suspensions ofpseudo-bentonite, titania or zirconia and/or hydrosols of any oxide,among others.

The non-ionic surfactant or tensoactive organic molecules to be usedaccording to the present invention may suitably be selected from thegroup consisting of ethoxylated alcohols, ethoxylated alkylphenols,amine oxides, ethoxylated amines and mixtures thereof. The non-ionicsurfactant may suitably be mixed in solution with the inorganic compoundso as to provide a molar ratio of ionic surfactant to inorganic speciesof between about 0.05 and about 20.

Any metal oxide or mixture of oxides can be prepared with the method ofthe present invention, as long as the appropriate pH value is selected.An indication of this value is given by the isoelectric point of therespective solid oxides or hydroxides, some of which are summarized inTable 1, and with an extensive compilation given by G. A. Parks,Chemistry Reviews, Vol. 65, pages 177 to 198, 1965.

                  TABLE 1                                                         ______________________________________                                        MATERIAL     ISOELECTRIC POINT                                                ______________________________________                                        Silica       1.8 to 2.2                                                       Alumina      8.0 to 9.2                                                       Titania      4.7 to 6.2                                                       Magnesia     11 to 12                                                         Iron Oxide   5.2 to 7.4                                                       ______________________________________                                    

The isoelectric point mean value for the materials of TABLE 1, as usedherein, are set forth in TABLE 2.

                  TABLE 2                                                         ______________________________________                                                     ISOELECTRIC POINT                                                MATERIAL     MEAN VALUE                                                       ______________________________________                                        Silica       2.00                                                             Alumina      8.60                                                             Titania      5.45                                                             Magnesium    11.50                                                            Iron Oxide   6.30                                                             ______________________________________                                    

In accordance with the invention, the solid porous inorganic materialobtained in accordance with the invention has a high void volume, atleast about 0.1 cc/g, attributable to tortuous channels with a meandiameter between about 15 Å and about 100 Å and a narrow sizedistribution of less than or equal to about 30 Å, and having stabilityfor use in thermal and hydrothermal treatments and processes. Thematerial is preferably also a short range order material as discussedabove.

As set forth above, during solvent extraction, the non-ionic surfactantis extracted and removed from intimate contact with the inorganicmaterial, thereby vacating mesopore-sized tortuous channels having thedesired mean diameter between about 15 Å and about 100 Å, anddistributed in a narrow size distribution no more than 30 Å wide thatrender accessible a high concentration of surface hydroxyl groups, whichconcentration can be controlled, if desired, through calcination.

Calcining is preferably carried out, if desired, at a temperature ofbetween about 200° C. and about 800° C., for a period of at least about1 hour. Of course, different materials may require different calcinationtimes and temperatures for a proper control of the hydroxyl groupconcentration.

It should be noted that the total volume of mesopore void volume formedin the final product depends upon the size and concentration of thenon-ionic surfactant in the starting solution. Further, the actual sizeof mesopore-sized channels depends upon the size or molecular weight ofthe organic molecules. Thus, the amount and size of organic molecule tobe used in solution may be selected so as to provide the desiredmesopore total void volume and mesoporous channel size.

The amount and size of the mesoporous-sized void volume can also beselectively controlled by adding organic water-insoluble compounds tothe mixture of the inorganic species and the non-ionic surfactant. Thesewater-insoluble compounds combine with the hydrophobic tail of thesurfactant, and increase the size of the micelle around which theinorganic species condense, thus increasing the size and volume ofresulting mesopore-sized channels in the material of the presentinvention. Suitable organic water-insoluble compounds according to theinvention may be selected from the group consisting of p-xylene,trimethylbenzene, triethylbenzene, dimethyladamantane and mixturesthereof.

By adjusting the mesoporous channel size and mesopore void volume, thetotal surface area can be controlled, which, in return, contributes toadjust the concentration of surface hydroxyl groups per gram ofmaterial.

As is the case with many catalysts, it may be advantageous to combinethe material of the present invention with a matrix material that hasdesirable thermal, mechanical or other properties. The material of thepresent invention may also be combined with other materials, such asdiluents to control the amount of conversion in a given process.Examples of such materials are aluminas, silicas, silica-aluminas,magnesias, titanias, zirconias, carbons and their precursors, clays andmixtures thereof. Also, precursors to the above mentioned materials canbe used, such as colloidal silica, alumina sols, suspensions ofpseudo-bohemite, titania, or zirconia, and hydrosols of any abovementioned oxides, among others. These materials may be combined with thematerial of the present invention during preparation or in apost-synthesis process. Also, these materials may be provided in part incolloidal form so as to facilitate extrusion of desired components.

The material of the present invention is useful as a catalyst forconversion of organic compounds, especially large hydrocarbons withmolecular sizes of about 15 Å or more. It is particularly useful forcatalyzing reactions that occur in the presence of acidic sites, inwhich the large hydrocarbon molecule is converted into products of lowermolecular weight or into more valuable isomers. Examples of suchreactions are involved in processes such as cracking, hydrocracking andisomerization. In such processes the material of the present inventionpresents various advantages over conventional catalysts. The largemesopore size and void volume allow large hydrocarbon molecules toeasily access the catalytically active sites located on the material,thereby minimizing diffusional constraints. The improved diffusionthrough channels also allows the primary products from thetransformation and or conversion of the large hydrocarbon molecule toexit the material before secondary reactions can take place, therebyretarding or even avoiding the formation of undesirable secondaryproducts such as coke which could eventually plug the channels ordeactivate catalytic sites on the material.

It may also be advantageous to incorporate into the material of thepresent invention minor amounts of metals as catalytic components,especially noble metals such as platinum, rhodium, rhenium, palladium oriridium, or Group VIII metals such as nickel, iron or cobalt, or GroupVI metals such as chromium, molybdenum or tungsten, or mixtures thereof.Additional active materials which may suitably be deposited on thesupport material of the present invention include Group IVB metals suchas titanium, zirconium and mixtures thereof, Group VB metals such asvanadium, niobium, tantalum and mixtures thereof, and rare earth metalsindividually or in mixtures. Of course, active metals such as theforegoing may suitably be incorporated through impregnation withsolutions of the desired metal. These metals may be present in theirmetallic state, or as oxides, sulfides or mixtures thereof. These metalscould for example provide the material of the present invention withdesired catalytic properties for processes such as hydrotreatment,hydroisomerization, hydrocracking, hydrogenation and/or reforming, toconvert large hydrocarbon molecules into more valuable products.

The material of the present invention is particularly useful when thedesired application involves metals as catalytic components dispersed onsilica. With the material of the present invention, surface hydroxylgroups of silica are present in high concentrations and act as anchoringsites that allow the effective dispersion of large amounts of metals ascatalytic components. The opposite situation has been observed withconventional forms of silica, which have been found to be poor supportsfor metals precisely due to low concentration of surface hydroxylgroups. According to the present invention, active metals and the likecan be dispersed over the support of the present invention to providefor metal dispersion of at least about 15%, preferably at least about20%, and further advantageously to provide for a total metal area of atleast about 0.10 m² /g, preferably at least about 0.25 m² /g.

The material of the present invention may also be advantageously used asa sorbent for the selective separation of one or more components in afeed. The narrow size distribution of mesopore-sized channels and thelarge void volume allow for separation of components in the feed by sizeexclusion of molecules. The walls of the material of the presentinvention provide for sites that can be modified through incorporationof molecules that contain specific functional groups with affinitytoward specific components in the mixture, allowing their separationfrom the feed. Examples include the incorporation of amines topreferentially adsorb acidic components in a feed, or chelating agentsthat separate metal contaminations off a stream. Also, these sites onthe walls of the material of the present invention can be used toincorporate compounds that can control the hydrophilicity of theenvironment within the pores or channels, advantageously allowing theseparation of polar from non-polar components in a feed.

Although the material of the present invention is useful in thetreatment of any hydrocarbon molecule, it is particularly advantageouswhen used for the treatment of large molecules that are too big to fitinto the channels of more conventional catalysts and/or sorbents. Thematerial of the present invention is especially suited for the treatmentof high boiling point hydrocarbon fractions in crude oils such asatmospheric and vacuum gas oils, high boiling point products fromprocesses such as catalytic cracking, thermal cracking, lube productionand the like and non-distillable fractions from crude oil or fromconversion processes such as residual feeds. The material of the presentinvention could also be utilized with feeds of non-petroleum origin.

The inorganic composition of the present invention is also ideallysuited to be used as a starting material for the incorporation of activematerials such as aluminum, for example in the form of alumina and thelike, so as to provide an amorphous silica-alumina which is useful inmany commercial processes. This material is acidic due to the electroninteraction between neighboring Al and Si atoms. It is desirable tomaximize the number of acid sites on such a composition, and this can beaccomplished by maximizing the amount of aluminum or other activematerial which is tetrahedrally coordinated with the silicon andbridging oxygen atoms.

In connection with this aspect of the present invention, it has furtherbeen found that the amount of aluminum or other active material which istetrahedrally coordinated with the silicon and bridging oxygen atoms isenhanced by providing the maximum possible number of hydroxyl groups inthe walls of the starting material. This can be accomplished inaccordance with the present invention, particularly by extracting thenon-ionic surfactant using a solvent as set forth above, withoutcalcination until after active metals are deposited on the material.Alternatively, the number of hydroxyl groups can be controlled ordirected, if desired, through calcination after the extraction step.

An inorganic composition can be prepared in accordance with the presentinvention which has substantially the same amount of hydroxyl groups assilica gel, with the added advantage that the material of the presentinvention is both thermally and hydrothermally stable, in contrast to asilica gel composition, the porosity of which collapses when subjectedto calcination. It is believed that the superior thermal andhydrothermal stability of the material of the present invention,compared to conventional silica gel forms, and despite both havingsubstantially the same amount of surface hydroxyl groups, is the resultof differences in the detailed structure of their walls. Evidence ofthis includes the longer relaxation times (T1) for Q³ and Q⁴ species in²⁹ Si solid state NMR experiments, for the material of the presentinvention, compared to amorphous silica gels.

Due to the additional stability of the composition of the presentinvention, active materials such as aluminum, for example alumina saltand the like, can be provided on the inorganic composition of thepresent invention, for example through controlled deposition, so as toadvantageously provide a final inorganic porous material, with activematerial deposited thereon, which can be used as a catalyst for a widevariety of commercial processes such as those involved in oil refining,and the petrochemical and fine chemical industries.

In accordance with this embodiment of the invention, silica and aluminummay be provided so as to form a ratio of Si/Al suited to a desirableapplication. Generally, it is preferred that the Si/Al ratio be lessthan or equal to about 500. Further, the silica composition of thepresent invention having a high number of hydroxyl groups can be used toprovide a composition including aluminum wherein at least about 60% wt.of the aluminum is tetrahedrally coordinated to the silicon and bridgingoxygen atoms as desired. As discussed below, (Example 3, FIG. 3) acomposition according to the present invention including tetrahedrallycoordinated aluminum exhibits a nuclearmagnetic resonance spectrumhaving essentially a single band centered at about 50 ppm.

In preparation of the intermediate product material in accordance withthe present invention, suitable solvent for use in extraction includesmethanol, ethanol, propanol, water, 2-methoxy-ethanol, 2-ethoxy-ethanoland mixtures thereof, especially mixtures of an alcohol and water, andsolvent extraction is preferably carried out by exposing the material toa flow of the solvent at a temperature of between ambient or roomtemperature and about 100° C. in a soxlet or a press filter.

As set forth above, a wide variety of active materials may be depositedupon the intermediate product porous material of the present invention,especially on silica based material, so as to provide effective andstable catalyst for a wide variety of different processes. Suitableactive materials which can be deposited on the intermediate productmaterial include active metals such as aluminum and the like asdiscussed above, as well as other active materials which may serve asnitrile absorbers such as those described in U.S. patent applicationSer. No. 08/529,759, and CO₂ adsorbents such as those described in U.S.Pat. No. 5,087,597.

The following examples further demonstrate the advantageouscharacteristics of the inorganic composition and process for preparationof same in accordance with the present invention.

EXAMPLE 1

In this example, a porous silicate composition is provided according tothe invention.

An acid solution of non-ionic surfactant was formed by mixing 17.7 g ofwater, 9.1 g of HCl (37% wt) and 1.1 g para-nonyl phenol ethoxylatedwith fifteen moles of ethylene oxide per mole of alkylphenol(C9H19--Ph--O--(CH2--CH2--O) 14--CH2--CH2--OH, where Ph is phenylgroup). The solution was mixed with 2.1 g of tetraethylorthosilicate(TEOS) (98% wt) for 2 minutes at room temperature, giving rise to aclear solution with the following molar composition:

    1 SiO.sub.2 :0.10 C9H19(EO)15:9.00 HCl:127.50 H.sub.2 O

This clear solution was placed in a sealed 60 ml teflon-wall reactor,where it was kept at 20° C. for 24 hours, and then heated to 60° C. for6 more hours. After this treatment a white solid was formed. Thisproduct was separated from the liquid by filtration, and washed withwater several times. The surfactant was then extracted from the productby flowing through the solid a boiling mixture of ethanol in a soxletsystem for 6 hours. The final product was dried at 80° C. under reducedpressure. The total removal of the surfactant in the material wasverified by infrared spectroscopy and thermogravimetric analysis.

The mesopore size distribution of the calcined material was determinedfrom its equilibrium N₂ adsorption isotherm, according to ASTM StandardPractice D 4641. The N₂ adsorption isotherm for the calcined material isshown in FIG. 1. The isotherm has an inflection point at P/P₀ equal to0.18, corresponding to the filling of pores 25 Å in average diameter.Beyond P/P₀ values of 0.80, the N₂ adsorption isotherm is essentiallyflat, indicating that the material does not contain pores larger than100 Å in diameter. The well defined edge in the adsorption isothermaround its inflection point indicates that the material has a narrowsize distribution of mesopores. This is better illustrated by plottingthe derivative of the N₂ adsorption volume as a function of porediameter, which for the calcined material is shown in FIG. 2. Thisfigure indicates that the void volume associated to mesopores in thematerial can be allocated to a narrow size distribution with channels nolarger than 40 Å in diameter.

The volume associated to pores 15 Å to 100 Å in diameter is equal to0.43 cc/g, as determined from equilibrium N₂ adsorption capacity atrelative P/P₀, pressures between 0.05 and 0.8.

The total surface area of the material, measured from the N₂ adsorptionisotherm, and according to the B.E.T. model, is equal to 1055 m² /g. Thesurface hydroxyl group concentration, measured from the signal intensitybetween 0 and 5 ppm on a ¹ H MAS NMR spectrum is equal to 4.47 mmol/g,and the material is indeed a material in accordance with the presentinvention.

The presence in the electron diffraction pattern (EDP) of a halo 0.0334Å⁻¹ in radius, indicates that the product of this example contains shortrange order arrays with a d-spacing (repeat distance) of 30 Å and it isindeed an embodiment of the material of the present invention.

To demonstrate the enhanced thermal stability of the material of thepresent invention, the product of this example was treated in a flow ofair for 18 hours at 500° C. After treatment, the material maintained itsoriginal porous structure; that is, a halo in the EDP with 0.0334 Å-1,radius, indicative of short range order with a d-spacing of 30 Å, a voidvolume of 0.36 cc/g, as determined from the equilibrium N₂ adsorptioncapacity at a relative P/P₀ pressure between 0.05 and 0.8, a narrow poresize distribution between 15 Å and 35 Å, centered around 25 Å, as shownby a well defined inflection point at P/P₀ equal to 0.21 in the N₂adsorption isotherm, and a surface area of 900 m² /g, as determined fromthe N₂ adsorption isotherm, according to the B.E.T. model.

To further demonstrate the enhanced hydrothermal stability of thematerial of the present invention, the product of this example wastreated in a flow of 100% steam for 3 hours at 823 K. After treatment,the material maintained its original properties; that is, a void volumeof 0.3 cc/g, as determined from the equilibrium N₂ adsorption capacityat relative P/P₀ pressures between 0.05 and 0.8, a narrow pore sizedistribution between 15 Å and 25 Å, centered around 20 Å, as shown by awell defined inflection point at P/P₀ equal to 0.18 in the N₂ adsorptionisotherm, a surface area of 850 m² /g, as determined from the N₂isotherm, according to the B.E.T. model, and a halo in the EDP with a0.0334 Å⁻¹ radius, indicative of short range order with a d-spacing of30 Å.

EXAMPLE 2

This example described the use of a source of silicate different thatTEOS.

An acid solution of non-ionic surfactant was formed by mixing 21.7 g ofwater, 9.1 g of HCl (37 wt %), 0.53 g of para-nonyl phenol ethoxylatedwith fifteen moles of ethylene oxide per mole of alkylphenol (C₉ H₁₉--Ph--O--(CH₂ --CH₂ --O)14--CH₂ --CH₂ --OH, where Ph is a phenyl group).The solution was mixed with 2.46 g of sodium silicate (SiO₂ 28.86 wt %,Na₂ O 8.94 wt %) for 2 minutes at room temperature, giving rise to asolution with the following molar composition:

    1 SiO.sub.2 :0.06 C.sub.9 H.sub.9 (EO)15:9.60 HCl:132.04 H.sub.2 O

This solution was placed in a sealed 60 mL Teflon-wall reactor, where itwas kept at 20° C. for 6 hours, and then heated to 80° C. for 6 morehours. After this treatment a white solid was formed. This product wasseparated from the liquid by filtration, and washed with water severaltimes. The surfactant was then extracted from the product by flowingthrough the solid a warm mixture of water/alcohol in a press filter. Thefinal product was dried at 80° C. under reduced pressure. The totalremoval of the surfactant in the material was verified by infraredspectroscopy and thermogravimetric analysis.

The mesopore size distribution of the extracted material was determinedfrom its equilibrium N₂ adsorption isotherm, according to ASTM StandardPractice D4641. The isotherm has an inflection point at P/P₀ equal to0.20, corresponding to the filling of pores 22 Å in average diameter.The volume associated to pores 15 Å to 100 Å in diameter is equal to 0.6cc/g. The total surface area of the material, measured from the N₂adsorption isotherm, and according to the B.E.T. model, is equal to 955m² /g. The surface hydroxyl group concentration, measured from thesignal intensity between 0 and 5 ppm on a ¹ H MAS NMR spectrum is equalto 4.06 mmol/g.

To demonstrate the enhanced thermal stability of the material of thepresent invention, the product of this example was treated in a flow ofair for 18 hours at 400° C. After treatment, the material maintained itsoriginal porous structure; that is a void volume of 0.6 cc/g, asdetermined from the equilibrium N₂ adsorption capacity at a relativeP/P₀ pressure between 0.05 and 0.8, a narrow pore size distributionbetween 15 Å and 35 Å, centered around 22 Å, as shown by a well definedinflection point at P/P₀ equal to 0.20 in the N₂ adsorption isotherm,and a surface area of 955 m² /g, as determined from the N₂ adsorptionisotherm, according to the B.E.T. model.

EXAMPLE 3

This example demonstrates the properties of several samples of catalystmaterial prepared in accordance with the present invention and includingcontrolled deposit of active materials.

A silica based material, prepared according to the method described inExample 1, was put in contact with a solution of Al(NO₃)₃. The pH of thesolution was adjusted to 4.5 with the addition of NH₄ OH, and theresulting mixture was stirred for one hour to facilitate theincorporation of Al species on the surface of the material. Theresulting product was filtered, washed with water and dried at 80° C.for 16 hours. The sample was then calcined in a flow of air for 16 hoursat 500° C. The amount of Al to be incorporated was adjusted by varyingthe concentration of the Al(NO₃)₃ solution that was put in contact withthe solid. The textural properties and Si/Al ratio of the resultingmaterials (identified as F1 to F3) are summarized below in Table 3. Allof the samples, after calcination, have a pore volume equal to 0.4 cc/g,BET surface areas higher than 800 m² /g, and narrow pore sizedistributions, centered around 22 Å.

Table 3 also presents the textural properties and Si/Al ratio of aconventional silica-alumina material. This material, identified as B1,was prepared by precipitation of a suspension of silica-alumina made ofsodium silicate (29% wt SiO₂) and sodium aluminate (49% wt Al₈ O₃), at aSi/Al molar ratio of 15. Precipitation was induced by decreasing the pHof the solution to 7 by acid addition. After washing it, the precipitatewas dried at 80° C. for 16 hours and calcined at 500° C. for 4 hours.This material has a pore volume of 0.37 c/g, a BET surface area of 117m² /g, and a broad pore size distribution, centered around 126 Å.

                  TABLE 3                                                         ______________________________________                                                                           BET                                        Sample     Si/Al   Vp         dp   S.A.                                       ID         (molar) (cc/g)     (Å)                                                                            (m.sup.2 /g)                               ______________________________________                                        F1         16      0.41       21   863                                        F2         77      0.41       21   863                                        F3         133     0.39       21   840                                        B1         15      0.37       126  117                                        ______________________________________                                    

In all of the samples prepared in accordance with the present invention(F1 to F3), at least 80% of the aluminum is tetrahedrally coordinated tothe silica, after calcination at 500° C. in air. On the contrary, in thesample prepared using conventional silica (B1), a large fraction of thealuminum (more than 50%) is octahedrally coordinated.

The presence of tetrahedrally coordinated aluminum has been determinedusing 27Al Magic Angel Spinning Nuclear Magnetic Resonance (²⁷ Al MASNMR). This technique is widely used for this purpose, because itgenerates clearly differentiated signals for tetrahedrally andoctahedrally coordinated aluminum. FIG. 3, shows the results of thesetests for samples F1 and B1. The large signal at approximately 50 ppmfor F1 indicates that almost all of the aluminum is tetrahedrallycoordinated, while the broad band ranging from -40 to 70 ppm for B1indicates the presence of both tetrahedrally and octahedrallycoordinated aluminum, with a large proportion being octahedrallycoordinated. Thus, the process of the present invention clearly providesa greater concentration of aluminum in a tetrahedrally coordinatedconfiguration, as desired. This larger fraction is believed to beresponsible for the higher catalytic activity in hydrocarbon conversion,observed for the material of the present invention. As an example, thecatalytic properties for hydrocarbon cracking and alcohol de-hydrationreactions for the materials of the present invention (F1 to F3), arecompared to those of conventional silica-alumina material (B1).

An evaluation of the catalytic properties for iso-propanol dehydrationof the material of the present invention (F1 to F3), compared to thoseof a conventional amorphous silica-alumina are shown in Table 4. Thetest was carried out in a fixed bed reactor under the followingconditions: temperature of 200° C., flow of iso-propanol of 1 ml/hr, andflow of carrier gas (N₂) of 7 ml/min. The catalytic activity of all ofthe tested materials, prepared according to the present invention, issubstantially higher than that of the conventional silica-aluminacatalyst. This is the case, even for the F3 sample, which has a total Alcontent almost 10 times lower than that of the conventional material.

                  TABLE 4                                                         ______________________________________                                                     iso-propanol                                                     Sample ID    conversion (%)                                                   ______________________________________                                        F1           80                                                               F2           82                                                               F3           45                                                               B1            8                                                               ______________________________________                                    

The superior catalytic properties of the material of the presentinvention are also evident, when employing a more demanding reactionsuch as the cracking of n-decane. The tests were carried out in a pulsereactor under the following conditions: pulse length 25s, temperature530° C., flow of n-decane 1.5 ml/hr, flow of carrier gas (N₂) 4 ml/minand mass of catalyst of 50 mg. The results of this evaluation aresummarized in Table 5 below. The conversion obtained with F1 is morethan 10 times higher than that of B1, despite the fact of both havingsimilar Si/Al ratio.

                  TABLE 5                                                         ______________________________________                                                      Si/Al   n-decane                                                Sample ID     (molar) conversion (%)                                          ______________________________________                                        F1            16      38                                                      B1            15       3                                                      ______________________________________                                    

The generation of acidity in the material of the present invention canalso be tested using pyridine adsorption. The infrared spectrumresulting from this test for two of the samples prepared in accordancewith the present invention (F1 and F3) is shown in FIG. 4. The presenceof bands at 1456, 1543 and 1623 cm⁻¹ are clear indications that thepyridine is interacting with both Bronsted and Lewis acid sites in thematerials, thereby indicating that the material is in fact highlyacidic.

EXAMPLE 4

This example demonstrates the ability of the material of the presentinvention to disperse active catalytic phases, and in particular noblemetals.

A sample of material prepared in accordance with the present invention,as described in Example 2 above, and identified as F4 was employed as asupport for Pt and Pd dispersed particles. In the case of Pt, thematerial was impregnated with the required amount of a solution ofhexachloroplatinic acid (H₂ PtCl₆) at a pH of 3 to achieve nominalcontents of 0.5 wt % and 1.0 wt %. In the case of Pd, the metal wasimpregnated with an aqueous solution of palladium chloride (PdCl₂) toachieve a nominal Pd content of 0.5 wt %. For comparison, Pt was alsoimpregnated on a conventional silica support, identified as B2, with atotal pore volume of 0.74 cc/g and a BET surface area of 137 m² /g,employing the same procedure previously described, in order to achieve anominal Pt content of 0.5 wt %.

The metal dispersions were determined from H₂ chemisorption experiments.The results of these tests are summarized in Table 6. For the case ofPt, the total metal area and the metal dispersion achieved whenemploying the material of the present invention as a support issubstantially higher than the levels achieved with a conventional SiO₂support. In the case of Pd, the total metal area and metal dispersionachieved when employing the material of the present invention as asupport are also very high. These results indicate the ability of thematerial of the present invention to effectively disperse high loadingsof metal particles, making it ideally suited for catalytic applications.

                  TABLE 7                                                         ______________________________________                                                                            Total                                                         Metal      Metal                                                                              metal                                                Dispersed                                                                              loading    disp.                                                                              area                                      Support ID Metal    (wt %)     (%)  (m.sup.2 /g)                              ______________________________________                                        F4         Pt       0.5        22   0.27                                      F4         Pt       1.0        22   0.55                                      F4         Pd       1.0        70   3.10                                      B2         Pt       0.5         2   0.02                                      ______________________________________                                    

This invention may be embodied in other forms or carried out in otherways without departing from the spirit or essential characteristicsthereof. The present embodiment is therefore to be considered as in allrespects illustrative and not restrictive, the scope of the inventionbeing indicated by the appended claims, and all changes which comewithin the meaning and range of equivalency are intended to be embracedtherein.

What is claimed is:
 1. A composition of matter, comprising an inorganicporous metal oxide material having wall portions defining mesopore-sizedchannels having a mean diameter of between about 15 Å and about 100 Åand a narrow diameter distribution of less than or equal to about 30 Å,said material having a void volume from said mesopore-sized channels ofat least about 0.1 cc/g and a surface area of at least about 500 m² /gand having a number of hydroxyl groups of at least about 1.5 mmol ofhydroxyl groups per gram of material, and exhibiting thermal andhydrothermal stability at temperatures up to about 500° C.
 2. Acomposition of matter according to claim 1, wherein said material has ashort range order.
 3. A catalytic composition of matter, comprising aninorganic porous metal oxide material having wall portions definingmesopore-sized channels having a mean diameter of between about 15 Å andabout 100 Å and a narrow diameter distribution of less than or equal toabout 30 Å, said material having a void volume from said mesopore-sizedchannels of at least about 0.1 cc/g, and a catalytically active metaldeposited on said inorganic porous material, said catalytically activemetal being dispersed over said inorganic porous material so as toprovide a metal dispersion of at least about 15%.
 4. A catalyticcomposition according to claim 3, wherein said active material isselected from the group consisting of noble metals, Group VIII metals,Group VI metals and mixtures thereof.
 5. A catalytic compositionaccording to claim 3, wherein said active material is selected from thegroup consisting of platinum, rhodium, rhenium, palladium, iridium andmixtures thereof.
 6. A catalytic composition according to claim 3,wherein said active material is selected from the group consisting ofnickel, iron, cobalt and mixtures thereof.
 7. A catalytic compositionaccording to claim 3, wherein said active material is selected from thegroup consisting of chromium, molybdenum, tungsten and mixtures thereof.8. A catalytic composition according to claim 3, wherein said activematerial is selected from the group consisting of titanium, zirconiumand mixtures thereof.
 9. A catalytic composition according to claim 3,wherein said active material is selected from the group consisting ofvanadium, niobium, tantalum and mixtures thereof.
 10. A catalyticcomposition according to claim 3, wherein said active material isselected from the group consisting of rare earth metals and mixturesthereof.
 11. A catalytic composition according to claim 3, wherein saidinorganic porous material is silica.
 12. A catalytic composition ofmatter according to claim 3, wherein said inorganic porous material hasa surface area of at least about 500 m² /g.
 13. A catalytic compositionof matter according to claim 3, wherein said inorganic porous materialhas a surface area of at least about 800 m² /g.
 14. A catalyticcomposition of matter according to claim 3, wherein said material has ashort range order.